The present invention generally relates to optical fibers and more particularly, to a device for detachably clamping an end portion of an optical fiber used for transmitting laser beams of high output, which end portion is fixed or joined to a mating end portion of another optical fiber.
Conventionally, in devices for clamping end portions of optical fibers, it has been generally so arranged, as shown in FIG. 1a, that in the case where an end portion of an optical fiber 1 is fixed, the end portion of the optical fiber 1 is fitted into an aperture of a cylindrical sleeve 2 having been subjected to high precision machining and then, the sleeve 2 having the end portion of the optical fiber 1 fitted thereinto is fitted into a highly precisely machined bore of an adaptor 3 such that the end portion of the optical fiber 1 is clamped in position. Meanwhile, in the known devices, it has been so arranged, as shown in FIG. 1b, that in the case where the end portion of the optical fiber 1 is joined to a mating end portion of another optical fiber 4, the end portions of the optical fibers 1 and 4 are fitted into the apertures of the sleeves 2, respectively and then, the sleeves 2 having the end portions of the optical fibers 1 and 4 fitted thereinto, respectively are, respectively, fitted into the highly precisely machined bores of an adaptor 5 such that the end portions of the optical fibers 1 and 4 are clamped in position.
However, in the prior art devices, adhesive is used at the time when the end portion of the optical fiber is fitted into the sleeve and fixed in the sleeve. In the case where laser beams of high output are transmitted by the optical fiber, the adhesive is rather absorbent of the laser beams. Accordingly, the known devices have such an inconvenience that since the laser beams leak out of outer peripheral surfaces of the optical fiber so as to be absorbed into the adhesive, the adhesive is so heated as to be molten, thereby aggravating reliability of the known devices. Furthermore, the prior art devices have such a disadvantage that since the end portion of the optical fiber is fixed in the sleeve by the adhesive, it is impossible to detach the end portion of the optical fiber from the sleeve.